In her 20s and 30s, Kami Semick was on the corporate track, logging 50-hour work weeks. But when everybody else headed out for happy hour, she'd run, bike, or swim. "I found that being outside and moving my body helped me focus and be creative on the job," she says. After the high-tech bubble burst, she and her husband had a baby, and the family moved to Bend, Ore., where she found herself surrounded by athletes, preparing for triathlons, trail, ski, and bike races.

"Everywhere I looked, there were people training for something," she says. That's when her ultrarunning career took off.

She entered her first 50-K just hoping to finish. The race—31 miles of single-track trails starting at 7,000 feet with 4,500 feet of elevation gain—sounded like her idea of a perfect day, "a day out in nature with just single-track and sunny skies."

Semick finished second in the race, and was hooked. She has been a leader in the sport, with a series of wins and course records at 50-K, 50-miles, and 100-K. She won every race she ran last year, including the IAU 100-K World Cup in Belgium, the IAU 50-K World Trophy in Gibraltar, the USATF 50-K National Championships, and the USATF 50- Mile Trail championships. She's excelled at shorter distances as well, as she won the 2008 Portland Marathon in 2:45:54, and won the 2004 Seattle Marathon in 2:53.

Semick started getting interested in Comrades about three years ago, after learning about the race, and the devastating toll that HIV/AIDS has taken on one of the communities surrounding the course. South Africa has the world's highest number of people living with HIV, and the most AIDS-related deaths. The area surrounding the Comrades course, the KwaZula Natal region, has the highest rate of HIV infection in the world; 40 percent of the adult population is HIV positive. Because of that, the area also has the highest rate of orphans in the world. She, along with North Face athletes Michael Wardian and Nikki Kimball, are raising money for Starfish Charity to help those children.

"I started digging into the issue, and I couldn't turn away," says Semick. "This is the reason why I am running Comrades in 2010. I want to make a difference in the lives of these children. I also want to be competitive. I plan on giving the race everything I have."

What do you like about ultrarunning?I love the spirit of the people involved in the sport and the challenge. At longer races—50 miles or more— at the start most people still have the spirit of "we are about to embark on an adventure." Anything can happen in these races—weather, stomach issues, trail obstacles, wildlife sightings, bodies rebelling—whatever. And most of the people I encounter are encouraging and supportive regardless of gender, position in the race, or how good or bad they are feeling. At the finish line, all the runners have stories about their journeys. And regardless of how we place, we are all equals because we have finished a grand adventure.

What is your regular training schedule like these days?I took most of December off from running—my annual break—so I am now just working my mileage back up. I'm currently running in the high 90s to 110 miles per week; I plan on being around 100 to 110 miles per week during hard weeks and backing down to 60 to 70 miles per week for easy weeks, and keeping this cycle through most of March and April. My two key quality workouts continue to be tempo runs and either hill repeats or track workouts, plus one long run on the weekend.

What—if any—kind of special training will you do for Comrades that's different from your regular routine?Long downhill running on pavement will be the challenge. I have plenty of uphill running skills to apply to the course, but the sustained downhill run in the last 20-K of the race will be new. I plan on a doing a few key long downhill runs on pavement to prepare for these conditions. In Bend, we have a couple of long roads that drop between 3,000 feet and 1,000 feet of elevation in 18 miles and 10 miles respectively. I plan to use these roads to work on leg turnover and downhill form.

You've been so dominant in the international arena. What kind of impact has that had—if any—on your ambitions as a runner?Maybe it helps tie my ambitions as a person with my ambitions as a runner. As a mom, I want to set a good example for my daughter. I want to make a difference to those in need. Racing at the international level may help by offering more visibility which I can then redirect to do others who are in need.

What would it mean to have an American win such a legendary event? I would be very proud to have any or all of us somewhere on the podium. I would be even more proud to come as athletes from the United States and not only leave footprints on the pavement of the course but make a difference in the lives of the children in the surrounding communities.

After Comrades, what other races are on your calendar?Comrades is my only road race. I hope to return primarily to the trails for the remainder of the year. I'd like to compete in the 2011 World Trail Ultra Championships, and the IAU 100-K World Cup in Winschoten, the Netherlands, in 2011.

Tell me about the effort to raise funds for Starfish.Three years ago in the REI in Bend, I gave a presentation on ultrarunning. After the talk, a member of the audience, Clifton Pieters, a native South African, came up and talked to me about Comrades, and told me he was raising money for children in South Africa who have been orphaned by AIDS. The more I researched the issue, the more it became clear that giving money at the grass-roots level is the most effective way to help the community. That's where Starfish came in. It's a small but very effective organization that is on the ground in communities hardest hit by HIV. Starfish invests in community-based organizations providing care and support to orphaned and vulnerable children. Working with Starfish, we identified a community that's visible on the Comrades course. Within the community, the project we're raising funds to support is known as "Vukukhayne," which means "Arise and Shine." It is this community's hope that they and their country will arise and shine and be examples to the world. I think about "Arise and Shine" every time I roll out of bed for a run.